More precisely, the invention relates to a radiocommunication module. Remember that the radiocommunication module is an essential element of a radiotelephone. It hosts and executes a main software (commonly called “radiocommunication software” or “GSM software”) that in particular performs wireless communication functions (radiocommunication) and controls various other hardware elements (screen, keyboard, loudspeaker, etc.) of the radiotelephone.
Normally (first application), the radiocommunication module is included in a terminal (or ME for “Mobile Equipment”) that cooperates with a SIM (Subscriber Identity Module) card.
Other applications are now envisaged for the above mentioned radiocommunication module.
In particular, it has been proposed to integrate the radiocommunication module in devices other than radiocommunication terminals but that still require a wireless communication function (second application). For example, telemetry devices (for reading meters), alarm devices or bank card readers.
It has also been proposed to supply the radiocommunication module in independent form (third application); it is then qualified as a modem. This type of modem does not contain any hardware man-machine interface element (screen, keyboard, loudspeaker, etc.). It is designed to cooperate with a terminal equipment (supporting a client software), that does have hardware man-machine interface elements. In particular, but not exclusively, the terminal equipment may be a microcomputer. In general, the terminal equipment hosts and executes a client driver software that controls the radiocommunication module, using a set of driver commands in the AT format. The AT (for ATtention command) commands enable the Terminal Equipment (TE) to request the radiocommunication terminal to which it is connected to perform some predetermined actions. To achieve this, the main software (hosted on the radiocommunication module) comprises means of executing AT commands sent to it by the client driver software (hosted on the terminal equipment).
For further information about AT commands, refer firstly to the ETSI “GSM 07.05” and “GSM 07.07” standards, and secondly to the ITU-T recommendation V25ter which are inserted herein by reference.
In general, a radiocommunication module can be driven by a terminal equipment using AT commands not only within the framework of the above mentioned third application (radiocommunication module forming a modem), but also within the context of the first and second applications mentioned above (radiocommunication module included in a radiocommunication terminal or other system).
In other words, regardless of what application is envisaged, the radiocommunication module may be driven by a terminal equipment with which it cooperates (usually through a serial link). In this case, a client driver software (comprising a “client external application”), hosted and executed by the terminal equipment, sends AT commands to a main software, hosted and executed by the radiocommunication module, so that the radiocommunication module can execute them.
As shown in FIG. 2, operation of the existing technique used for terminal equipment to drive a radiocommunication module may be summarized as follows:                step “1”: the client external application (client driver software) 2 sends an AT command;        step “2”: the serial link 5 transmits the AT command to the AT command execution means 4 included in the main software 3 hosted and executed by the radiocommunication module 1;        step “3.”: the execution means 4 execute the AT command;        step “4”: after execution, the execution means 4 send an AT response to the client external application 2;        step “5”: this response is sent through the serial link 5;        step “6”: the client external application 2 receives the response.        
Each of these steps is shown in FIG. 2 by a circle in which the number of the step concerned is entered. The same convention is adopted in the following figures related to this invention (and that are described in detail in the remainder of the description).
The existing technique for driving a radiocommunication module by terminal equipment has several disadvantages.
Firstly, it requires two sets of resources (processor and memory). The radiocommunication module comprises a processor and a memory (first set of resources) and the terminal equipment also has a processor and a memory (second set of resources). Therefore, the existing technique mentioned above is expensive in terms of equipment and energy consumption.
Another disadvantage of the above mentioned existing technique is that the radiocommunication module is entirely driven by the terminal equipment. The client driver software hosted on and executed by the terminal equipment is the “master”, while the main software hosted and executed by the radiocommunication module, is the “slave”.
The purpose of the invention is particularly to overcome these disadvantages with the state of the art.
More specifically, one purpose of this invention is to provide a technique for driving a radiocommunication type module using a client driver software, that is simple and inexpensive (in terms of hardware and energy consumption).
Another purpose of the invention is to provide such a driver technique enabling the radiocommunication module to supervise (and act upon) the driving procedure, when driving is carried out by a terminal equipment. In other words, it is desired that the radiocommunication module does not only act as a slave.